Usually, the IP address of a network device to be connected to an IP network is set at a certain value such as “192.168.0.1” in advance at the time of shipment from a factory. To use such a network device, first a user changes its IP address to a value that is suitable for a network environment of the user and then starts using it.
In ordinary network environments, device connection setting information that is necessary for a communication over an IP network is managed in the above-described manner. However, in industrial networks of factories etc., in many cases, a network device is installed before setting of its connection setting information.
In such a case, it is necessary to go to an installation site of a network device and carry out work of setting prescribed connection setting information. If network device are installed in a wide area, setting work requires much labor.
Even if network devices are located at distant places, prescribed settings can be made over an IP network as long as the respective network devices have different IP addresses. However, it is highly likelihood that the same IP address is set for network devices at the time of shipment from the factory. In this case, it is necessary to go to installation sites of the network devices and make necessary settings.
For example, where an IP network includes a wireless network which is constructed according to the wireless communications standard ISA 100.11a, a system manager, a gateway, and a backbone router (BBR) are connected to the IP network. One or more network devices exist on the IP network, and plural identical network device may be connected to the IP network.
FIG. 5 is a block diagram showing an example network which is part of a conventional connection setting information managing system. As shown in FIG. 5, a system manager 2, a gateway 3, and three backbone routers 4-6 are connected to an IP network 1 as network devices. A setting tool 7 for setting, for each of the network devices 2-6, connection setting information which allows it to perform a communication over the IP network is also connected to the IP network 1. Although field devices such as a flowmeter, a pressure meter, and temperature meter are also connected to the backbone routers 4-6, they are not shown in the figure.
As shown in FIG. 5, the IP addresses of these network devices are set at initial addresses in advance: “192.168.10.1” is set for the system manager 2, “192.168.10.2” is set for the gateway 3, and a common value “192.168.100.1” is set for the backbone routers 4-6.
With the above configuration, the setting tool 7 sets connection setting information for each of the network devices 2-6 according to the following procedure. It is assumed that the IP network 1 to which the network devices 2-6 are connected has been constructed in advance and each of the system manager 2, the gateway 3, and the three backbone routers 4-6 is connected to the IP network 1 in a state that it is only powered on (i.e., in a state at the time of shipment from a factory).
FIG. 6 illustrates how connection setting information is set for each of the system manager 2 and the gateway 3. To set connection setting information for each of the system manager 2 and the gateway 3, the IP address of the setting tool 7 is changed so that the setting tool 7 belongs to the same subnet as the two network devices 2 and 3 (in the example of FIG. 6, “192.168.0.10”→“192.168.10.10”).
Changing the IP address of the setting tool 7 so that the setting tool 7 belongs to the same subnet as the network devices 2 and 3 allows the setting tool 7 to access each of the network devices 2 and 3.
FIG. 7 illustrates how connection setting information is set for each of the backbone routers 4-6. To set connection setting information for each of the backbone routers 4-6, the IP address of the setting tool 7 is changed so that the setting tool 7 belongs to the same subnet as the backbone routers 4-6 (“192.168.0.10”→“192.168.100.10”). However, since the address was set for the backbone routers 4-6 at the time of shipment from a factory (in the example of FIG. 7, “192.168.100.1”), a communication cannot be performed normally between the setting tool 7 and each of the backbone routers 4-6.
In the example of FIG. 7, it is conceivable to make a setting over the IP network 1 by directly connecting the setting tool 7 to each of the backbone routers 4-6 or to make settings individually using a serial connection, an infrared communication, or the like.
As another method, unique IP addresses can be assigned to the network devices using a DHCP (dynamic host configuration protocol) for setting IP addresses (connection setting information) for respective network devices automatically.
Patent document 1 discloses a technique relating to a control system of a manufacturing facility which is configured to perform a wireless communication that complies with the wireless LAN standard IEEE 802.11a in the case of a backbone network and to perform a wireless communication that complies with the wireless LAN standard IEEE 802.11b or IEEE 802.11g in the case of a peripheral network.